This invention relates to a gripper and feeding apparatus for moving materials such as metal sheets or strip in production machines, particularly blanking presses or the like wherein the apparatus includes a gripper carrier guided on slide guides so that the carrier can reciprocate by means of a drive which is actuated by a pressure medium and carries controllable transport grippers for engaging and retaining the material during feeding movement to the press.
A feed mechanism is frequently used to intermittently supply sheet or strip material to a blanking press from which workpieces are stamped. Known feeding mechanisms for this purpose usually comprise two transport grippers for retaining the material during the feeding movement. The grippers are disposed on a carriage or the like forming a slide guide which is guided by two slide rods for longitudinal movement. While the transport grippers are situated in a plane of the material, the drive cylinder used to provide feeding movement is situated beneath the plane of the material. This construction and relationship of parts has a number of disadvantages. One such disadvantage arises from the fact that the point at which the force is applied by the drive cylinder to the material is offset from the plane of the material whereby there is considerable tilting force on the carriage or the like during transmission of a mechanical force. This reduces the force applied to the material, increases wear on the slide guide and also affects the accuracy of the feeding movement of the material. Moreover, regular lubrication is required for the slide guides which increases the cost of servicing the apparatus.